1. Field of the Invention
Embodiments of the present invention relate to aerial display system. More particularly, embodiments of the present invention relate to an optimized aerial display system for consumer display applications having a low cost plastic spherical mirror.
2. Description of the Background Art
Aerial display systems generate images that appear to float in the air several inches in front of the display device. Aerial display systems have been used for many years because of the novelty associated with a floating image.
Conventional aerial display systems are typically housed in a wooden structure that resembles a large box the size of a refrigerator. Inside the structure, a region for displaying the static item is in optical alignment with optical components that generate an aerial image of the static item. By way of example, a shoe or a food item may be positioned in the display region to generate a floating 2D image of the item. In some applications, the display region comprises a video display device, such as a cathode ray tube (CRT) or a liquid crystal display (LCD) that generates a floating video image. The HOLOVISION™ display system, developed by Provision Entertainment, the assignee of the present application, provides realistic floating three-dimensional video images using a high bright LCD that achieves a very black background rather than a grayish black background. HOLOVISION is a trademark of Provision Entertainment.
Unfortunately, conventional aerial display systems require a very large form factor for achieving a realistic floating or aerial image, are very heavy, and are very expensive. Thus, their use has been limited to commercial applications such as product demonstrations at conventions or trade shows or to display expensive objects such as jewelry or objects of museum quality.
Another problem with conventional aerial display systems arises from the expensive optical elements, specifically a beam splitter, a glass spherical mirror, and a circular polarizer, that are used to generate the floating image. For example, the spherical mirror is typically an expensive highly polished glass substrate with low distortion that costs over US $ 1,000 for an average sized display unit. Further, while the polarizer prevents a viewer's reflection from polluting the floating image, it is also a very expensive element.
Because of the high cost of conventional aerial display systems, such systems have not been widely adopted by many businesses and even fewer consumer applications include an aerial projection display system. Indeed, conventional aerial display systems are limited to museum and trade show applications where the high cost of the system can be justified by its ability to attract attention. Clearly, what is needed is a low cost aerial projection system that can be used for consumer and business applications. As interactive gaming achieves greater popularity, the ability to project three-dimensional objects from the computer display toward the viewer will enhance realism. Thus, there is a great need for a low-cost aerial display system that may be included as a part of a home entertainment system, computer display, or as part of an interactive gaming application, by way of example, rather than to limit the use of aerial projection systems to museums or trade show applications. What is also needed is an aerial projection system that may be used in both the home environment and in commercial applications in ambient lighting conditions. What is also needed is an aerial projection system that is lightweight and easily adaptable to a variety of applications without the constraint of using the heavy and expensive glass spherical mirrors used in the conventional aerial display systems.
Indeed, glass has been the conventional material of choice for use as spherical mirror. One of the most important reasons is because plastics technologies were not as developed as they are today. In other words, the tools and materials were not available as they are today. The metal mold tolerances and the resulting parts can be specified and held in the tens of thousandths of an inch. Materials used today are more sophisticated; the plastics are able to emulate the thermal stability and durability similar to that of glass, and to endure the type of operating conditions in the past that only glass could have tolerated. Glass spherical mirrors are expensive because of the secondary operations needed to prepare the mirror surface after it is heat formed or slumped to shape. These secondary operations include annealing, grinding and polishing. The annealing process is used to strengthen the glass so that it is strong enough to undergo the grinding and polishing operation, as well as adding the additional strength needed to resist breakage during usage. The grinding and polishing stages are necessary because of the limits of the tolerance capabilities of glass forming molds and the physical nature of glass. Unfortunately, the grinding and polishing stages require a considerable amount of manual processing for producing a finished product; therefore, they are often considered semi-automated processes.
In addition, Glass also has the serious drawbacks of breakage, weight, and expensive shipping costs. To try to overcome the limitations and drawbacks of glass, a low-cost glass forming process was developed. However, the low-cost glass forming process did not provide an acceptable surface finish, and the resulting cost reductions were not comparable to that of plastic. Clearly, what is also needed is a method and system for manufacturing a plastic part to reduce the weight of a spherical mirror to approximately one-third that of glass, and for making a low-cost plastic spherical mirror of comparable performance to glass spherical mirror.